This is obfuscated code. The only way you will be able to get the original class names is if you have the code before obfuscation. Unless the writer of the code left some holes in it, the only option is to go through the code and spend a lot of time refactoring the code to get rid of the obscurity and try and make some sense out of it, but it would probably be quicker to write your own application that does the same thing.
As an additional note, since the code is obfuscated, the code has the real class names. Even if you were to call a method that returned the class name, this is exactly what you should expect to get.
solved is it possible to get the C# class original name to improve the code readablity from obfuscated exe [closed]